Overpressure valve



Jan. 1925- 7 1,522,715

' L. DURR OVERPRESSURE VALVE Filed Sept. '3, 1921 INVENTORY Patented Jan. 13, 1925.

LUDWIG DIIRR, OF. FRIEDRIGHSHAFEN-ON-THE-BODENSEE, GERMANY, ASSIGNOR TO THE FIRM LUFTSCHIFFBAU ZEPIPELIN G. M. B. H., OF FRIEDRICHSHAFEN, GER- MANY.

Application filed September 3, 1921.

T 0 all whom it may concern Be it known that I, LUDWIG Dunn, a citizen of the Republic of Germany, residing at Friedrichshafen-on-the-Bodensee, Germany, have invented certain new and useful Improvements in Overpressure Valves (for which I have filed an application in Germany July 5, 1920), of which the following is a specification.

My invention refers to airships and more especially to the safety valves inserted in the walls of the gas cells of airships of the rigid type.

In the gas cells of rigid airships the safety valves are as a rule arranged symmetrically, which results in an equal pressure acting on all the valves. This arrangement, however, involves the disadvantage that each valve requires separate gas exhausts.

The present invention allows to discharge the gas of two adjacent cells into a common gas fine. If the valves heretofore used were arranged in adjacent walls of two adjacent cells there would, upon inclination, result different gas pressure, so that, for instance, the lower cell would discharge the gas earlier than the higher one, because a higher gas column is acting on the valve of the lower cell, whileon the upper cell there acts a smaller gas column.

It is an object of these drawbacks. In spite of the different pressures acting on the valves the gas is caused to be discharged simultaneously, the valve discs together with the additional weights combined with these discs creating a higher closing pressure on the valve of the lower cell and a lower pressure on the valve of the upper cell, than corresponds to the normal pressure predetermined by the power of the valve spring. The radially acting component of weight of the disc is taken up by a special supporting device. By suitably selecting the weight of the valve discs provision can be made for adjoining valves to discharg simultaneously at all inclinations of the airship in spite of the different gas pressures, haturally this arrangement involves the disadvantage that not only the load pressure of the valve disc of the lower cell, in which the gas pressure rises, is altered, but also the pressure of the upper cell in which it is practically independent from the inclination of the airship. Consequently my invention to avoid.

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Serial No. 498,585.

the upper cell valves blows off at a lower pressure than is required in respect to the tearing strength of the gas cell envelope.

The valves further blow off earlies in the inclined. position than in the horizontal, thus causingsome loss of gas. It is, however, possible to avoid these inconveniences by influencing the disc of the lower valve by a weight and leaving the loading pressure of the upper valve disc unaltered. This is attained by giving the additional weightthe form of a pendulum thus causing this weight to always bear on the lower valve disc.

I prefer using only a single pendulum weight common to both valves of a pair. In

order to obtain a normal lift of the valve disc the pendulum weight comes in contact with the disc only at a predetermined small inclination of the airship. Furthermore the weight of the disc of the lower valve acts still towards closing and the weight of the upper disc towards opening their respective valves. These faults, however, remain within limits set by accidental inaccuracies such as differences in the quantity of gas in the different cells and different weight of the supporting gas. However, these inconveniences can be avoided, including the. disturbance caused by the gas column which acts upon the valves also in the horizontal position of the airship and which changes somewhat at inclined positions, as also the disturbance arising through the weight of the valve disc in a case where the valves are arranged in the horizontal bottom of the cell. In such cases the pendulum weight must act indirectly, for instance, by means of bent levers or the like.

It is further possible to lessen these faults resulting from the weight of the valve disc by taking this weight into consideration in selecting the pendulum weight.

If a single pendulum weight only is pro vided for each valve, it can be arranged in such manner that it contacts with the valve disc even in th smallest inclination of the airship. If the distance between the valve disc surface and the pendulum weight is made about equal to one half of the valve lift, the distance will compensate the faultwhich results from the deviation of the pendulum weight while the valve is lifting.

In the drawings ailixed to this specification and forming part thereof an arrangement embodying my invention is illustrated diagrammatically by way of example. In the drawings Figure 1 is an axial longitudinal section through a part of an airship hull.

Figure 2 is a longitudinal section of the valves of two adjoining gas cells drawn to a larger scale, the difi'erent gas pres-v sures being here compensated by the weight of the valve discs.

Figure 3 is a similar view of a modification, the valves being balanced by means of pendulum weights.

Referringtothe drawings, the valves are fixed in adjoining 'end walls a, "b of the gas cells. I, II, respectively, the gases escaping into a common gas fine 0. Each valve consists of a ring 85 against which is pressed the valve disc e by a spring f mounted on the hoop g. The component E directed at right angles to the longitudinal axis of the airship and Which is equal to the weight G of the valve disc,is taken up by a flexible band it. The component I) acts on the valve of the gas cell I against the pressure of the gas column I-II-I, While the component D of the valve of gas cell II acts in opposite direction to "the component of the other valve, i. e. in the direction of the gas pressure. In the horizontal position of the airship the springs f 'which'are permanently under the same pressure, will close the valves, because in this case D is equal to Zero. I

In the modificationillustrated 'in Figure 3 the valves are again arranged in adjoining end walls 1 l of two gas cells. The valve discs m and m? are kept closed by tension springs n and 72?. A pendulum weight 0 is suspended from a point g 'by a wire or chain pand in accordance with the inclinations of the airship will swing free of the upper valve disc and comein contact with the lower valve disc, thereby increasing the valve pressure counteracting the gas pressure. I

I wish it to be understood that I do not desire to be limited to the exact details of construction described for obvious modifications will occur to a person sliilled'in the art.

I claim:

1. An airship comprising 'a plurality of gas cells, safety valves oppositely arranged in adjoining end walls of said cells, valve discs in said valves and closing springs acting on said discs, the weight o'fsaid'discs being such that upon inclination of said airship "the combined spring and disc 'pre'ssures suflice to counteract the tendency of the increased "gas pressure, of the lower gas cell to open'the lower valve.

2. An airship comprising a plurality of gas cells, safety valves oppositely-arranged in adjoining end walls of said cells, valve discs in said valves, closing spring-s acting on said discs and'meansextending at right angles to the longitudinal axis of said airship and attached to said discs @fOI holding same, theweight'of said discs being such that upon inclination of said airship the combined spring and disc pressure suffices to counteract the tendency of the increased gas pressure, of the lower cell to open the lower valve.

3. An airship comprising a plurality of gas cells, safety valves oppositely arranged in adjoining end walls of said cells, cover discs in said valves, closing springs acting on said discs and a pendulous weightsuspended in swinging contact with said idiscs, whereby upon i-nclinatiom'of said airship said weight will contact with the disc of the lowermost of said valves, the combined spring, disc and weight pressure :suificing :to counteract the tendency ott'the increased gas pressure, of the lower cell to open the lower valve. Y

41. An airship com-prising a plurality of gas cells, safety valves oppositely arranged in "adjoining end walls of said cells, cover discs vin-said valves and closing springs acting on said discs, the weight pressure. of said discs being adapted upon inclination of said 'airshipfto increase theweightpressure'on the lower valve and to decrease the weight pressure .on "the upper valve sui'iiciently, substantially to" compensate for the difference in "gas pressure "on both valves resulting from such 7 inclination, thereby providing for substantially simultaneous gas discharge from *both said adjacent safety valves.

"'5. An airship comprising a plurality of ,gas cells, safety valves oppositely arranged in adjoining end walls of said cells, cover discs in said valves, closing springsa'cting onsaid discs and means extending "at ri ght angles to the longitudinal axis of said airship and'attached to said discs for holding same, the weight pressure'o'f said discs being adapted upon inclination of said airship to increase the weight pressure on "the lower valve andto decrease the weight-pres sure on the upper valve sufliciently, substantially to compensate for the difierenc'e in gas pressure on both valves resulting fromsuch inclination, thereby providing for substantially simultaneous gas discharge from both said adjacent sa fety valves.

In testimony whereof I affix my signature in presence of 'two witnesses.

DR. L'UDIVIG DU'RR.

WVitnesses: I

HANs NEUMErsTER, WILHELM BERG. 

